Ice maker with freezing aid

ABSTRACT

An ice maker for fitting into a cooling or freezing appliance includes an ice-making tray which forms a plurality of ice-piece-producing cavities for producing one ice piece each. An air channel is formed above the ice-making tray, which serves to guide a cold air stream. There is provided a heat-dissipating structure including a metal material and having a plurality of heat-dissipating pins, each of which, in a freezing phase, projects from above, with a pin tip leading, into one of the ice-piece-producing cavities. In some embodiments, the heat-dissipating pins extend into and through the upper air channel, so that the cold air flowing in the air channel flows around shaft portions of the heat-dissipating pins situated inside the air channel. When the ice-piece-producing cavities are filled with water, the heat-dissipating pins immersed in the water ensure improved dissipation of thermal energy from the water, which accelerates freezing.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to an ice maker for fitting into a cooling or freezing appliance for domestic use.

2. Description of the Prior Art

Refrigerators for the domestic sector are nowadays frequently demanded that have an ice maker which allows ice pieces, for example in the form of ice cubes, to be produced automatically. The repeated manual filling of an ice-making tray with water and placing of the tray in a freezing compartment of the refrigerator is generally perceived as being inconvenient by users. Automatic ice makers automatically perform the functions of filling an ice-making tray with water and emptying the tray as soon as the water has frozen into ice pieces, without the involvement of the user.

In ice making, a high production rate is generally desired, that is to say the freezing process is to be kept as short as possible so that all the more ice pieces can be produced in a given period of time. In order to accelerate the freezing process, it has been proposed in DE 1 020 040 A to provide, for a resilient freezing tray made of a rubber or plastics material, a metal thermal bridge through a container bottom of each freezing container formed by the freezing tray, which thermal bridge establishes a heat-conducting connection between the inside of the container and the outside. The metal parts of the thermal bridges located outside the freezing containers form feet with which the freezing tray can be placed on a receiving plate in an ice-producing compartment of a refrigerator.

There are doubts as to whether, in the case of an ice-making tray which is to be operated manually by the user, that is to say manually filled with water and then placed in a freezing compartment of a refrigerator, the mere provision of metal parts which establish a heat-conducting connection between the inside of an ice-piece-producing cavity and the outside leads to a significant acceleration in ice production.

SUMMARY OF THE INVENTION

The present invention seeks ways in which ice production can effectively be accelerated in the case of an automatic ice maker.

In order to achieve this object, the invention starts from an ice maker for fitting into a cooling or freezing device for domestic use, comprising an ice-making tray, which forms a plurality of ice-piece-producing cavities for producing one ice piece each, and a channel wall arrangement for delimiting at least one air channel which serves to guide a cold air stream. According to the invention, there is provided in such an ice maker a heat-dissipating structure comprising a metal material and having a plurality of heat-dissipating pins, each of which, in a freezing phase, projects from above, with a pin tip leading, into one of the ice-piece-producing cavities, wherein the heat-dissipating structure has heat transfer surfaces which are in heat-conducting connection with the pin tips and against which there flows the cold air stream of a first air channel/upper air channel delimited by the channel wall arrangement.

In this solution, the heat-dissipating structure has heat transfer surfaces which are so arranged that they are situated, at least in the freezing phase, in the first air channel and are therefore struck by the cold air flowing therein. The heat-dissipating structure absorbs thermal energy from the water at the pin tips which project into the ice-piece-producing cavities from above, that is to say through the cavity openings of the ice-piece-producing cavities, so that they are in contact with the water which has been introduced into the ice-piece-producing cavities. At the heat transfer surfaces of the heat-dissipating structure situated in the first air channel, heat is transferred to the air of the cold air stream. The transfer of heat at the heat transfer surfaces situated in the first air channel is increased owing to the flow of the cold air. This results in increased heat transport from the pin tips of the heat-dissipating pins to the heat transfer surfaces of the heat-dissipating structure situated in the first air channel, which overall accelerates the freezing process.

It has been shown that, without an additional metallic freezing aid, ice formation generally begins in the region of the cavity walls of the ice-piece-producing cavities and from there gradually advances towards the central regions of the cavities. Freezing therefore frequently occurs last in the centre of the ice-piece-producing cavities. Against this background, it is provided in some embodiments that, in the freezing phase, each of the dissipating pins projects into the ice-piece-producing cavity in question without contact with the cavity walls. At least some of the heat-dissipating pins can project into the centre of the ice-piece-producing cavity in question in the freezing phase. Positioning the heat-dissipating pins at a distance from the cavity walls of the ice-piece-producing cavities, in particular in the middle of the cavities, can promote ice formation—in addition to ice formation starting from the cavity walls—also from a point situated inside the cavities, namely starting from the heat-dissipating pins.

In some embodiments, each of the dissipating pins is associated with a different one of the ice-piece-producing cavities, that is to say, a total of one heat-dissipating pin projects into each ice-piece-producing cavity. However, embodiments in which more than one heat-dissipating pin, for example two or more heat-dissipating pins, are associated with each ice-piece-producing cavity are of course not excluded.

For a good cooling action of the heat-dissipating pins it is proposed that, for at least some of the heat-dissipating pins, the depth of penetration of the pin into the ice-piece-producing cavity in question corresponds to at least one third or at least half or at least three fifths of the depth of the cavity. In this manner, early ice formation deep within the ice-piece-producing cavities can be promoted.

In some embodiments, the heat transfer surfaces against which the cold air stream of the first air channel flows are formed on pin shafts of at least some of the heat-dissipating pins. In other words, the heat-dissipating pins project with their shaft regions into the first air channel at least in the freezing phase.

In some embodiments, the heat-dissipating pins have a circular pin cross-section at least in the region of the pin tips entering the ice-piece-producing cavities. Outside the pin tips, that is to say, where the heat-dissipating pins are not in contact with the water in the ice-making tray, the pin cross-section can have a different geometry, although the heat-dissipating pins can of course have a circular cross-section substantially over their entire pin length. However, in particular in order to optimize the transfer of heat from the heat-dissipating pins to the cold air flowing in the first air channel, it can be expedient to choose a cross-sectional geometry other than a circular shape in those pin portions in which the cold air stream of the first air channel flows around the heat-dissipating pins. For example, a drop-shaped cross-sectional geometry is conceivable in those pin portions. Such a drop shape has a rounded shape on one side, for example, and tapers on the other side. The rounded side can face the inflowing cold air and the tapering side can be remote therefrom. In other embodiments, the heat-dissipating pins can have in a pin portion in which the cold air stream of the first channel flows around them one or more annular flanges, the flange plane of which is substantially parallel to the direction of flow of the cold air in the first air channel. Such annular flanges too can enlarge the surface around which the cold air of the first air channel flows and thus increase the transfer of heat from the heat-dissipating pins to the cold air.

In some embodiments, the first air channel/upper air channel runs above the ice-making tray, it being separated from the ice-making tray in the direction of the tray upper side of the ice-making tray by a channel-delimiting wall. The heat-dissipating structure extends through the channel-delimiting wall into the first air channel at least in the freezing phase. Because in these embodiments the first air channel is not open to the tray upper side of the ice-making tray, owing to the presence of the channel-delimiting wall, there is no risk, or at any rate only a substantially reduced risk, that the cold air flowing in the first air channel will carry with it moisture which can form by condensation of the water in the ice-making tray and could then precipitate in other regions of the cooling or freezing device outside the ice-piece-producing cavities. Such precipitation, with subsequent undesirable ice formation, is always to be feared when a cold air stream is in direct contact with the water in the ice-making tray. In the mentioned embodiments of the invention, such direct contact with the cold air flowing in the first air channel is prevented because of the channel-delimiting wall. A thermal bridge through the channel-delimiting wall can be realised, for example, if at least some of the heat-dissipating pins project through the channel-delimiting wall into the first air channel in the freezing phase.

In the mentioned embodiments, in which the first air channel is separated from the ice-making tray by a channel-delimiting wall, the first air channel can have a channel cross-section that is closed all round at least in a channel portion situated above the ice-making tray. For this purpose, the first air channel can be formed in the channel portion situated above the ice-making tray by a box element, for example.

It is to be expected that the freezing ice will adhere to the heat-dissipating pins projecting into the ice-piece-producing cavities. For this reason, there is provided in some embodiments a pin-release device which can be switched between an activated state and a deactivated state and which in the activated state effects the release of the heat-dissipating pins from frozen ice pieces which have been produced. Alternatively or in addition, the pin-release device can be configured to prevent the heat-dissipating pins from freezing to ice pieces. In the latter case, adhesion of the frozen ice to the heat-dissipating pins can be prevented in the freezing phase. The pin-release device can be configured, for example, to heat the heat-dissipating pins. When the heat-dissipating pins are heated, a molten film forms, which allows the ice pieces to be detached easily from the heat-dissipating pins. Because the molten film forms not on the outer surface of the ice pieces but in the region of an indentation formed in the ice pieces by the heat-dissipating pins, the risk that the ice pieces that have been produced will stick together when they are subsequently introduced into a collecting container, when the molten film freezes again, is low.

Alternatively or in addition to the provision of suitable heating means, the pin-release device can be configured to drive the heat-dissipating pins in rotation, in particular in oscillation-rotation, about a respective pin axis. By setting the heat-dissipating pins in a rotational movement, they can be freed from the ice pieces which have been produced, which are located in the ice-piece-producing cavities. This is the case in particular if the ice-piece-making cavities do not have a rotationally symmetrical shape, because the ice pieces are then prevented from rotating in the ice-piece-producing cavities by the rotationally unsymmetrical shape of the ice pieces. The rotational movement of the heat-dissipating pins can be, for example, an oscillating-rotating movement, that is to say can include a rotational movement to and fro with comparatively short strokes, similar to the movement known, for example, in the case of electric toothbrushes.

For driving the heat-dissipating pins in rotation, the pin-release device can comprise, for example, a toothed rod which is interlocked with at least some of the heat-dissipating pins and is driven by a motor for displacement in the longitudinal direction of the rod. If the ice-piece-producing cavities are distributed in the ice-making tray over a plurality of parallel rows of cavities, the toothed rod advantageously extends between two adjacent rows of cavities. In this manner, the heat-dissipating pins of both rows of cavities can be driven together by the toothed rod. If the ice-piece-producing cavities are divided into a total of two rows of cavities, all the heat-dissipating pins can be driven together via the toothed rod.

For emptying the finished ice pieces from the ice-making tray, a procedure is provided in some embodiments in which the heat-dissipating pins are first released from the ice pieces (for example by heating or rotational movement of the heat-dissipating pins, see above) and then the heat-dissipating pins are lifted out of the ice-piece-producing cavities and moved away from the ice-making tray. The ice-making tray is then rotated about a horizontal axis of rotation (horizontal in the fitted state of the ice maker in the cooling or freezing device) and additionally also twisted. Twisting of the ice-making tray requires a certain degree of elasticity of the ice-making tray at least in some tray regions, for which reason the ice-making tray is typically made of a plastics material or/and a rubber-elastic material, but in any case not of a metal material. Twisting of the ice-making tray serves to detach the ice pieces from the cavity walls of the ice-piece-producing cavities, so that the ice pieces are able to fall out of the rotated ice-making tray and fall into a collecting container situated beneath the ice-making tray. In order to be able to lift the heat-dissipating pins out of the ice-piece-producing cavities and later lower them back into them again, a corresponding pin-lifting device is provided in some embodiments. In order that the ice-making tray does not strike the heat-dissipating pins as it is rotated from an ice-producing rotational position (horizontal position in the fitted situation) into an ice-ejecting rotational position and is thereby prevented from rotating, the pin-lifting device is advantageously configured to lift the heat-dissipating pins out of the path of rotation of the ice-making tray. The lifting movement of the heat-dissipating pins can be linear, for example, or follow a more complex movement pattern.

The heat-dissipating pins can be in the form of metal pins of hollow or solid construction. Suitable as the metal material for the heat-dissipating structure are, for example, aluminium or/and copper.

In some embodiments, which do not require the first air channel and the heat-dissipating structure with the heat-dissipating pins, the channel wall arrangement delimits a second air channel/lower air channel which runs beneath the ice-making tray and is open on the lower side of the tray. In these embodiments too, it is possible to accelerate ice production by providing at least some of the ice-piece-producing cavities in the region of a cavity bottom with a heat-dissipating member comprising a metal material. The heat-dissipating member has a heat-absorbing surface which is exposed to the cavity interior of the ice-piece-producing cavity in question, and a heat transfer surface which is arranged so that the cold air stream of the second air channel can flow against it and is in heat-conducting connection with the heat-absorbing surface. In a comparable manner as in the case of the heat transfer surfaces of the heat-dissipating structure against which the cold air stream of the first air channel flows, increased transport of heat from the water in the ice-making tray to the outside via the heat-dissipating member is possible owing to the flow of the cold air stream of the second air channel against the heat transfer surface of the heat-dissipating member. This accelerated removal of thermal energy effects accelerated ice formation in the ice-piece-producing cavities.

In some embodiments, the heat-dissipating member comprises a peg body which passes through a bottom wall of the ice-piece-producing cavity in question, the heat-absorbing surface being formed on a peg head of the peg body. The peg head can have different shapes; for example, it can have the shape of a round head or of a conical head or of a countersunk head or, in conformity with the cavity contour of the ice-piece-producing cavities, it can have a depression (indentation) on the head upper side. The shaft portion of the peg body can be provided with a thread. This allows the peg body to be screwed through a screw hole in the bottom wall of the ice-piece-producing cavity in question. Alternatively, a thread-free form of the peg shaft can be chosen, for example as in the case of a rivet. In other embodiments, it is conceivable to insert the peg body into an injection mould for the ice-making tray during production of the ice-making tray and to inject the material of the ice-making tray around it.

To form the heat transfer surface, the heat-dissipating member can comprise a plate body which is connected to the shaft portion of the peg body and on the plate faces of which the heat transfer surface is formed. The plate body can be so oriented that its plate plane lies substantially parallel to the direction of flow of the cold air stream in the second air channel. This permits good heat dissipation from both plate sides of the plate body. The plate body can be in the form of a flat plate, but other plate geometries are also conceivable.

Where heat transfer surfaces and heat-absorbing surfaces are mentioned here, these are formed of the metal material of the heat-dissipating structure or of the heat-dissipating members, respectively, whereby that metal material may optionally have a non-metallic, for example adhesion-reducing, surface coating in the region of the heat-absorbing or heat transfer surface in question. In order to conserve the good heat-conducting properties of the metal material, such a surface coating is generally thin in comparison with the thickness of the metal material. Typical surface coatings have a layer thickness of not more than 500 μm or not more than 400 μm or not more than 300 μm or not more than 200 μm or not more than 100 μm.

The invention is described in greater detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of components of an ice maker according to an embodiment.

FIG. 2 is a top side view of the ice maker of FIG. 1.

FIG. 3 shows the ice maker of FIG. 1 in a longitudinal section.

FIG. 4 is a cross-section of the ice maker of FIG. 1 in an ice-producing state.

FIG. 5 is a cross-section of the ice maker of FIG. 1 in an ice-piece-ejecting state.

FIGS. 6a and 6b are a perspective view and a sectional view, respectively, of an ice piece produced using the ice maker of FIG. 1.

FIGS. 7a and 7b are a side view and a view from beneath, respectively, of a heat-dissipating pin which can be used in the ice maker of FIG. 1.

FIGS. 8a and 8b are corresponding views of a heat-dissipating pin having a different pin geometry.

FIGS. 9a and 9b are corresponding views of a heat-dissipating pin having yet a further changed pin geometry.

FIG. 10 is a cross-sectional view of components of an ice maker according to a further embodiment.

FIGS. 11a to 11c are views of different forms of a peg body of a heat-dissipating member which can be used in the ice maker of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Reference is first made to FIGS. 1 and 2. The ice maker shown therein is generally designated 10. It comprises as the central component an ice-making tray 12 which serves to produce ice pieces. The ice-making tray 12 forms a plurality of ice-piece-producing cavities 14 which can be filled with fresh water by means of a water supply device (not shown). By the action of cold, the water in the ice-piece-producing cavities 14 freezes. The ice maker 10 works by the so-called twisted tray principle, according to which the ice-making tray 12 is twisted in order to release the frozen ice pieces from the cavity walls of the ice-piece-producing cavities 14. In an ice-ejecting rotational position of the ice-making tray 12, the finished ice pieces are then able to fall out of the ice-making tray 12 and be caught in a collecting container (not shown) situated beneath the ice maker 10.

The ice maker 10 comprises a base frame 16, which in the example shown comprises two frame plates 18, 20 located opposite and at a distance from one another. The ice-making tray 12 is arranged between the two frame plates 18, 20 and is supported on the base frame 16. It is rotatable relative to the base frame 16 about an axis of rotation 22 which runs in the longitudinal direction of the tray. A drive unit 24 mounted on the base frame 16 serves to drive the ice-making tray 12 in rotation about the axis of rotation 22.

In the embodiment shown, an air channel is formed both beneath and above the ice-making tray, which air channels are charged with cold air during freezing operation of the ice maker 10. The cold air transports away thermal energy, which is transferred from the ice-making tray 12, or the water contained therein, to the surroundings, and thus accelerates the freezing process. The cold air has a temperature of between −10 and −30 degrees Celsius, for example. The lower air channel is designated 26 and is delimited between the tray underside of the ice-making tray 12 and a trough component 28 which is arranged beneath the ice-making tray 12 and at a distance therefrom, with the longitudinal direction of the trough parallel to the longitudinal direction of the tray. The trough component 28 forms a channel wall which delimits the air channel 26 at the bottom. The air channel 26 is delimited at the top by the ice-making tray 12. The cold air flowing in the air channel 26 therefore is in direct contact with the ice-making tray 12. The cold air is introduced into the air channel 26 via a mouthpiece 30, which is part of an air supply system (not shown) which includes a cold air source. Cold air passes from the mouthpiece 30 through an air passage 32 formed in the frame wall 18 into the air channel 26. In the air channel 26, the cold air flows in the longitudinal direction of the tray from one longitudinal end of the tray to the opposite longitudinal end of the tray, where it emerges, for example, into the space in which the ice maker 10 is fitted in a domestic cooling or freezing device. Alternatively, the cold air is purposively trapped in the air channel 26 at the end of its flow path and conveyed away.

The air channel 26—when viewed in a section orthogonal with respect to the longitudinal direction of the channel—is not necessarily closed all round. In the example shown, there is a gap between the longitudinal side walls of the ice-making tray 12 and the longitudinal edges of the trough component 28. Alternatively, it is conceivable to bring the trough component 28 in the region of its longitudinal edges up against the longitudinal side walls of the ice-making tray 12 so tightly that substantially no gap remains there and the air channel 26 is accordingly substantially closed all round.

By contrast, in the example shown, the air channel formed above the ice-making tray 12—when viewed in a section orthogonal with respect to the longitudinal direction of the channel—is closed all round. For the explanation of the upper air channel, reference will now additionally be made to FIGS. 3 and 4. It is designated 34 therein and is supplied with cold air from the air supply system via a further mouthpiece 36. Through a further air passage 38 formed in the frame wall 18, cold air passes from the mouthpiece 36 into the upper air channel 34. In the air channel 34, the cold air flows from the longitudinal end of the ice-making tray 12 adjacent to the frame wall 18 to the opposite longitudinal end of the tray, where it either emerges into the free space inside the cooling or freezing device or is purposively trapped and conveyed away.

The upper air channel 34 is formed by an auxiliary cooling module 40 which is arranged on the base frame 16 in such a manner that it is displaceable relative thereto, in particular can be moved upwards and downwards, and is a carrier for a plurality of heat-dissipating pins 42. The auxiliary cooling module 40 comprises a module base body 44 which in the longitudinal region of the ice-making tray 12 forms a channel housing 46 which is closed all round in cross-section. The housing interior of the channel housing 46 forms the upper air channel 34.

One of the heat-dissipating pins 42 of the auxiliary cooling module 40 is associated with each of the ice-piece-producing cavities 14 of the ice-making tray 12. In the example shown, the ice-making tray 12 has a total of ten ice-piece-producing cavities 14, which are divided between two parallel rows of cavities each having five ice-piece-producing cavities 14. Accordingly, the auxiliary cooling module 40 has a total of ten heat-dissipating pins 42 which are arranged in a pattern corresponding to that of the ice-piece-producing cavities 14. In the ice-producing state of the ice maker 10 shown in FIGS. 1 to 4, the heat-dissipating pins 42 are oriented vertically, that is to say their pin axis—shown in one of the heat-dissipating pins 42 in FIG. 4 and designated 48—is oriented vertically, based on the fitted state of the ice maker 10 in the cooling or freezing device. The heat-dissipating pins 42 are arranged centrally in relation to their associated ice-piece-producing cavity 14 and project with a lower pin tip 50 into the associated ice-piece-producing cavity 14. The heat-dissipating pins 42 pass through the upper air channel 34 over its entire height. In a lower channel wall 52 formed by the channel housing 46, an opening 54 is formed for this purpose in association with each of the heat-dissipating pins 42; likewise, in an upper channel wall 56 formed by the channel housing 46, an opening 58 is formed in association with each of the heat-dissipating pins 42. The heat-dissipating pins 42 are pushed through the openings 54, 58 in the channel walls 52, 56, with the result that a shaft portion 60 of their pin shaft is situated in the air channel 34 and the cold air flowing therein flows around it.

The heat-dissipating pins 42 (which can also be referred to as cooling pegs) comprise a metal material with good thermal conductivity, for example copper or aluminium, optionally coated with a plastics surface coating. In the example of FIG. 4 shown, they are in the form of bodies made of solid material (solid bodies); it will be appreciated that the heat-dissipating pins 42 can alternatively be in the form of components that are hollow on the inside. At least those surface regions of the heat-dissipating pins 42 that enter the water in the ice-making tray 12, and those surface regions around which the cold air in the upper air channel 34 flows, should be formed of the metal material. Moreover, there should be a metal thermal bridge between those surface regions of each heat-dissipating pin 42, in order to effect good transfer of the thermal energy absorbed at the metal surfaces immersed in the water to the metal surfaces that are in the air stream of the upper air channel 34.

The ice-piece-producing cavities 14 are rotationally unsymmetrical in the peripheral direction of the cavities, so that the resulting ice pieces—when the ice-making tray 12 is viewed from above—have a correspondingly rotationally unsymmetrical contour. FIG. 6a shows an example of an ice piece 62 having a pyramid-like shape. In its pyramid base face, designated 64, the ice piece 62 has a central, elongate blind hole 66, which forms as a result of the pin tips 50 of the heat-dissipating pins 42 plunging into the water in the ice-making tray 12. It can be seen from the sectional view according to FIG. 6b that the depth of the blind hole 66, designated t, is more than half and specifically slightly more than two thirds of the total height, designated h, of the ice piece 62. The heat-dissipating pins 42 enter the ice-piece-producing cavities 14 to a corresponding depth in the ice-producing state of the ice maker 10. It will be appreciated that the mentioned ratio of the depth t of the blind hole 66 to the height h of the ice piece 62 requires the ice-piece-producing cavities 14 to be filled with water to a maximum height. This maximum height is generally defined by separating walls or separating webs, by means of which adjacent ice-piece-producing cavities 14 are separated from one another.

As soon as the water in the ice-making tray 12 has frozen to form ice pieces, the ice-making tray 12 is emptied and then filled with fresh water for the production of further ice pieces. For emptying the ice-making tray 12, it is necessary to release the heat-dissipating pins 42 from the ice pieces. It is to be assumed that, during the freezing phase, the water freezes to the pin tips 50 of the heat-dissipating pins 42 projecting into the ice-piece-producing cavities 14. In order to release the heat-dissipating pins 42 from the ice pieces, a pin-release mechanism is provided in the embodiment in question here for driving the heat-dissipating pins 42 in rotation, in particular in oscillation-rotation, about their respective pin axis 48. Owing to the rotationally unsymmetrical shape of the ice-piece-producing cavities 14, the ice pieces are not able to rotate with the heat-dissipating pins 42 when they are rotated. Ice bridges between the heat-dissipating pins 42 and the ice pieces 62 can thus be broken by rotation of the heat-dissipating pins 42. A comparatively small stroke of the heat-dissipating pins 42 can be sufficient to release them from the ice pieces 62. For example, it can be sufficient to rotate the heat-dissipating pins 42 through an angle of rotation of only a few degrees, for example 5 or 10 degrees. In particular, it can be expedient to subject the heat-dissipating pins 42 not only to a single rotation in one direction of rotation but to rotate them several times in succession in opposite directions of rotation, that is to say in an oscillating manner, in order to ensure that all the heat-dissipating pins 42 are reliably released from the ice pieces. Alternatively, the heat-dissipating pins can be set in rotation during the freezing phase, so that the ice pieces are prevented from the outset from freezing to the heat-dissipating pins 42. It is conceivable to actuate the heat-dissipating pins 42 during the entire freezing phase or only during part of the freezing phase. Instead of actuating the heat-dissipating pins 42 in the form an optionally oscillating rotary movement, it is conceivable to heat the heat-dissipating pins 42, for example by means of electrical heating wires (not shown) running in the pins.

In the example shown, the mechanism for releasing the heat-dissipating pins 42 from the ice pieces comprises a toothed rod 68 which is arranged above the upper channel wall 56 of the upper air channel 34 between the two rows of heat-dissipating pins 42 and has a tooth path to each row of pins. The toothed rod 68 is driven for to and fro movement in the longitudinal direction of the rod, that is to say in the direction of the axis of rotation 22, and is in interlocking engagement with a bevel 70 of each heat-dissipating pin. The bevels 70 are, for example, plastics toothed wheels which are seated on the heat-dissipating pins 42, which are otherwise made of metal. A motor, in particular electric motor, drive unit (not shown) for the toothed rod 68 can be integrated into the auxiliary cooling module 40 and is accommodated, for example, in a housing section 72 of the module base body 44.

After the heat-dissipating pins 42 have been released from the ice pieces 62, the heat-dissipating pins 42 are moved vertically upwards in order to retrieve the lower pin tips 50 from the ice pieces 62. Although it is conceivable in principle to lift the heat-dissipating pins 42 relative to the module base body 44 for this purpose, the embodiment shown is based on the assumption that the auxiliary cooling module 44 as a whole, that is to say including the module base body 44, is lifted relative to the ice-making tray 12. A corresponding lifting device comprises a motor, in particular an electric motor, drive unit, which can be formed by the drive unit 24, for example. In this case, a single, common drive motor for the rotary drive of the ice-making tray 12 and the lifting actuation of the auxiliary cooling module 40 is sufficient. Alternatively, it is conceivable to provide a drive unit that is separate from the drive unit 24 for the lifting actuation of the auxiliary cooling module 40.

In the example shown, the module base body 44 is designed with post sections 74 in the corner regions of a rectangle which corresponds to the contour of the ice-making tray 12. Two of these post sections 74 are adjacent to the frame wall 18, the other two post sections 74 are adjacent to the frame wall 20. Between the post sections 74 and the frame walls 18, 20 there can be produced, for example, a linear guide, for example in the form of a vertical groove, into which a vertical rail engages.

The mechanism for lifting the auxiliary cooling module 40 is configured to move the auxiliary cooling module 40 vertically upwards to such a degree that the heat-dissipating pins are moved completely out of the path of rotation not only of the ice-making tray 12 but also of the trough component 28. For emptying the ice-making tray 12, the trough component 28 is in the example shown rotated about the axis of rotation 22 together with the ice-making tray 12. FIG. 5 shows a situation in which the auxiliary cooling module 40 has been moved linearly upwards out of its working position according to FIG. 4 into a non-operative position, and the ice-making tray 12 together with the trough component 28 has been rotated through 90 degrees into an ice-ejecting rotational position. It will be appreciated that rotation through less than 90 degrees may be sufficient or rotation through more than 90 degrees may even be necessary in order to reach the ice-ejecting rotational position. When the ice-ejecting rotational position of the ice-making tray 12 is reached, the drive unit 24 is still operated further for a short time in order to effect the mentioned twisting of the ice-making tray 12, which leads to the release of the ice pieces 62 from the cavity walls of the ice-piece-producing cavities 14. After the ice-making tray 12 has been emptied, it (together with the trough component 28) is rotated back into the ice-producing rotational position according to FIG. 4 again. The auxiliary cooling module 40 is then moved vertically downwards into its working position according to FIG. 4 again. It will be appreciated that the rotary movement of the ice-making tray 12 and the vertical movement of the auxiliary cooling module 40 do not have to be carried out at different times. Instead, an at least partial time overlap between the two movements is conceivable. In particular, there can be complete time synchronism between the rotary movement of the ice-making tray 12 and the vertical movement of the auxiliary cooling module 40.

FIGS. 7a, 8a and 9a show examples of different geometries of the heat-dissipating pins. In order to distinguish between the variants shown in these figures, the same reference numerals as in the preceding figures are chosen, but with the addition of a different lower case letter in each case. FIGS. 7b, 8b and 9b show associated plan views from beneath of the heat-dissipating pin in question.

In the embodiment according to FIGS. 7a, 7b , the heat-dissipating pin 42 a has in the shaft region 60 a an approximately drop-like cross-sectional shape with a wider drop region 76 a and a tapering drop end region 78 a. In the wider drop region 76 a, the shaft portion 60 a is designed with a run-on tip 80 a in the example shown. The heat-dissipating pin 42 a is fitted with an orientation such that the cold air in the view of FIG. 7b meets the heat-dissipating pin 42 a from the right and flows around it in the direction towards the left.

In the variant according to FIGS. 8a, 8b , the heat-dissipating pin 42 b is again designed in the region of its shaft portion 60 b with a drop-like cross-sectional shape with a wider drop region 76 b and a tapering drop end region 78 b. In contrast to the variant according to FIGS. 7a, 7b , the wider drop region 76 b of the heat-dissipating pin 42 b is designed with a circular-arc-shaped cross-sectional contour, that is to say without a run-on tip. In the fitted state, the orientation of the heat-dissipating pin 42 b is such that the cold air in the view according to FIG. 8b meets the heat-dissipating pin 42 b from the left and flows around it in the direction towards to the right.

Finally, in the variant of FIGS. 9a, 9b , the heat-dissipating pin 42 c has in the region of its shaft portion 60 c a rotationally symmetrical shape overall. In order to increase the region of contact with the cold air flowing around it, the shaft portion 60 c of the heat-dissipating pin 42 c is designed with a plurality of annular flanges 82 c which are arranged one above the other and are spaced apart axially, and which surround the shaft portion 60 c completely. The annular flanges 82 c can be formed, for example, by placing metal annular plates on a peg which serves as the basis for the heat-dissipating pin 42 c and soldering or welding them to the peg.

The two heat-dissipating pins 42 which can be seen in each of the two sectional views according to FIGS. 4 and 5 are not shown with exactly the same construction in the two figures. This serves merely to illustrate that different geometries can in principle be used for the heat-dissipating pins 42. However, all the heat-dissipating pins 42 in the same ice maker are preferably of the same construction.

Reference will now be made to FIG. 4 again. There will be seen therein a heat-dissipating member 84 which is arranged in the region of the cavity bottom of one of the ice-piece-producing cavities 14. The heat-dissipating member 14 a is composed of a peg body 86 and a plate body 88. The peg body 86 has a peg head 90 and a shaft portion 92, which can be provided with a thread, for example. The shaft portion 92 of the peg body 86 passes through an opening (not provided with a reference numeral) which is formed in the cavity wall in the region of the cavity bottom of the ice-piece-producing cavity 14 in question. The peg head 90 is situated inside the ice-piece-producing cavity 14, while the shaft portion 92 projects downwards through said opening in the cavity wall into the air channel 26. The plate body 84 is there seated on the shaft portion 92 and fastened thereto, for example by screwing. Both the peg body 86 and the plate body 88 are made of a metal with good thermal conductivity, for example aluminium or copper. In the region of the peg head 90, the heat-dissipating member 84 is able to absorb thermal energy from the water in the ice-piece-producing cavity 14 in question and transmit it via the shaft portion 92 to the plate body 88. Thermal energy can there be transferred from the heat-dissipating member 84 to the cold air flowing in the air channel 26. The heat-dissipating member 84 accordingly forms a thermal bridge between the inside of the ice-piece-producing cavity 14 in question and the cavity exterior situated inside the air channel 26. The plate body 88 is oriented with its plate plane substantially parallel to the direction of flow of the cold air in the air channel 26. In this manner, the cold air flows substantially uniformly along both plate sides of the plate body 88.

For reasons of clarity, only one of the ice-piece-producing cavities 14 is shown equipped with a heat-dissipating member 84 in FIG. 4. It will be appreciated that all the ice-piece-producing cavities 14 of the ice-making tray 12 can each be equipped with a heat-dissipating member 84. Accordingly, in FIG. 5, a heat-dissipating member 84 is shown in association with each of the two ice-piece-producing cavities visible therein.

The provision of the heat-dissipating members 84 is a measure which can be taken alternatively or in addition to the provision of the auxiliary cooling module 40 with the heat-dissipating pins 42. The heat-dissipating members 84 also constitute a freezing aid which can ensure more rapid freezing of the water in the ice-piece-producing cavities 14. An embodiment of the ice maker with heat-dissipating members in the region of the cavity bottom of the ice-piece-producing cavities but without upper heat-dissipating pins is shown in FIG. 10. In this figure, components which are the same or have the same effect are provided with the same reference numerals as in the preceding figures, but again with the addition of a lower case letter. FIG. 10 illustrates above all that different head geometries can be used for the heat-dissipating member 84 d. While a flat form of the peg head 90 d has been chosen for the heat-dissipating member 84 d on the right of the two in FIG. 10, the peg head 90 d of the heat-dissipating member 84 d of the left-hand ice-piece-producing cavity 14 d in FIG. 10 is in the form of a spherical head. All the heat-dissipating members 84 d within the same ice maker 10 d advantageously have the same construction, that is to say have the same head shape of the peg head 90 d. Different head geometries are shown in FIG. 10 merely to illustrate that different head geometries are conceivable in general.

FIGS. 11a, 11b and 11c show, in a perspective view, different head geometries for the peg head 90 d of the peg body 86 d. FIG. 11a shows a spherical head shape, FIG. 11b shows an embodiment with a sunk (hollowed-out) head upper side, and FIG. 11c shows a conical head shape.

Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims. 

What is claimed is:
 1. An ice maker for fitting into a cooling or freezing appliance for domestic use, comprising an ice-making tray, which forms a plurality of ice-piece-producing cavities having cavity walls for producing one ice piece each; a channel wall arrangement for delimiting at least one air channel comprising a first air channel which serves to guide a cold air stream; and a heat-dissipating structure comprising a metal material and having a plurality of heat-dissipating pins, each of which, in a freezing phase, projects from above, with a pin tip leading into one of the plurality of ice-piece-producing cavities of the ice-making tray, wherein the heat-dissipating structure has heat transfer surfaces which are in heat-conducting connection with the pin tip of each of the heat-dissipating pins and against which there flows the cold air stream of a first air channel delimited by the channel wall arrangement.
 2. The ice maker according to claim 1, wherein, in the freezing phase, each of the plurality of heat-dissipating pins projects into a corresponding ice-piece-producing cavity of the plurality of ice-piece-producing cavities in question without contact with the cavity walls.
 3. The ice maker according to claim 1, wherein at least some of the plurality of heat-dissipating pins project into a center of a corresponding ice-piece-producing cavity in the freezing phase.
 4. The ice maker according to claim 1, wherein each of the plurality of heat-dissipating pins is associated with a different one of the plurality of ice-piece-producing cavities.
 5. The ice maker according to claim 1, wherein, for at least some of the plurality of heat-dissipating pins, the depth of penetration of a corresponding pin into the corresponding ice-piece-producing cavity in question is selected from the group consisting of at least one third, at least half and at least three fifths of the depth of the cavity.
 6. The ice maker according to claim 1, wherein the heat transfer surfaces against which the cold air stream of the first air channel flows are formed on pin shafts of at least some of the heat-dissipating pins.
 7. The ice maker according to claim 1, wherein the first air channel runs above the ice-making tray and is separated from the ice-making tray in the direction of a tray upper side of the ice-making tray by a channel-delimiting wall, and in that the heat-dissipating structure extends through the channel-delimiting wall into the first air channel in the freezing phase.
 8. The ice maker according to claim 7, wherein at least some of the plurality of heat-dissipating pins project through the channel-delimiting wall into the first air channel in the freezing phase.
 9. The ice maker according to claim 7, wherein the first air channel has a channel cross-section that is closed all round at least in a channel portion situated above the ice-making tray.
 10. The ice maker according to claim 1, further comprising a pin-release mechanism which can be switched between an activated state and a deactivated state and which is configured, in the activated state, to effect a release of the plurality of heat-dissipating pins from frozen ice pieces which have been produced or/and to prevent the heat-dissipating pins from freezing to ice pieces.
 11. The ice maker according to claim 10, wherein the pin-release mechanism is configured to heat the plurality of heat-dissipating pins, or to drive the plurality of heat-dissipating pins in rotation about a respective pin axis, or to heat the plurality of heat-dissipating pins and to drive the plurality of heat-dissipating pins in rotation about a respective pin axis.
 12. The ice maker according to claim 11 wherein the rotation is oscillation-rotation about a respective pin axis.
 13. The ice maker according to claim 11, wherein the pin-release device comprises a toothed rod which is interlocked with at least some of the plurality of heat-dissipating pins and is driven by a motor for displacement in a longitudinal direction of the rod.
 14. The ice maker according to claim 1, further comprising a pin-lifting device which is configured to lift the plurality of heat-dissipating pins out of and into the ice-piece-producing cavities.
 15. The ice maker according to claim 14, wherein the ice-making tray is mounted for rotation about an axis of rotation between an ice-producing rotational position and an ice-ejecting rotational position, and in that the pin-lifting device is configured to lift the plurality of heat-dissipating pins out of a path of rotation of the ice-making tray.
 16. The ice maker according to claim 1, wherein at least some of the plurality of heat-dissipating pins are each in the form of a hollow pin or in the form of a solid pin.
 17. The ice maker according to claim 1, wherein the metal material of the heat-dissipating structure comprises aluminium or/and copper.
 18. The ice maker for fitting into a cooling or freezing appliance for domestic use, the ice maker comprising: an ice-making tray, which forms a plurality of ice-piece-producing cavities for producing one ice piece each; and a channel wall arrangement for delimiting at least one air channel which serves to guide a cold air stream, wherein the channel wall arrangement delimits a lower air channel which runs beneath the ice-making tray and is open on a lower side of the tray, and at least some of the plurality of ice-piece-producing cavities are each equipped in the region of a cavity bottom with a heat-dissipating member comprising a metal material, which heat-dissipating member has a heat-absorbing surface which is exposed to a cavity interior of the at least some of the ice-piece-producing cavities in question, and a heat transfer surface which is so arranged that the cold air stream of the second air channel flows against the heat transfer surface and which is in heat-conducting connection with the heat-absorbing surface.
 19. The ice maker according to claim 18, wherein the heat-dissipating member comprises a peg body which passes through a bottom wall of a corresponding ice-piece-producing cavity of the at least some of the plurality of ice-piece-producing cavities, and in that the heat-absorbing surface is formed on a peg head of the peg body.
 20. The ice maker according to claim 19, wherein the heat-dissipating member comprises a plate body which is connected to a shaft portion of the peg body and on which the heat transfer surface is formed.
 21. The ice maker for fitting into a cooling or freezing appliance for domestic use, the ice maker comprising: an ice-making tray, which forms a plurality of ice-piece-producing cavities for producing one ice piece each; and a channel wall arrangement for delimiting an upper air channel which serves to guide a cold air stream above the ice-making tray and a lower air channel which runs beneath the ice-making tray and is open on a lower side of the tray, and at least some of the plurality of ice-piece-producing cavities are each equipped in the region of a cavity bottom with a heat-dissipating member comprising a metal material, which heat-dissipating member has a heat-absorbing surface which is exposed to a cavity interior of the at least some of the ice-piece-producing cavities in question, and a heat transfer surface which is so arranged that the cold air stream of the second air channel flows against the heat transfer surface and which is in heat-conducting connection with the heat-absorbing surface. 